The objective of this study is the exploration of the relationship between organization and performance in primary health care. The study question is: "What organization variables are related to a high level of performance?" Performance has been limited to qualities "uniquely important" to the delivery of primary health care as distinguished from medical care. Operational criteria for performance were developed normatively, using the Nominal Group Process with consumers, from a wide range of ethnic-income groups, and primary care "experts." Organizational variables are structural and contextual. They will be identified by students of organizational behavior, and selected for their relevance to performance of primary care systems. In the year for which continued funding is sought, the study would: 1. Develop indicators and measurement instruments for three performance areas. Select approximately 30 organizational variables and refine the corresponding data collection methods. 2. Collect data via questionnaire mailed to approximately 150 group practices (in which primary care, delivered with fee-for-service payment, predominates) in California. Explore the validity and reliability of the measures and collect in-depth data via site visit to 30 of the 150 group practices. 3. Evaluate the relationship between the performance and organizational variables. Refine these conclusions and combine them with the inferences drawn from the 30 site visits. This is the first phase of a study in which these processes will be repeated with an increased number of performance variables for additional organizational modes.